A DSC Distress call is received by your vessel and your transceiver frequency display reads: Transmit = 4207.5 kHz and Receive = 4207.5 kHz with J3E emission -- what information can you infer from this?
Correct Answer
The DSC call requested voice on 4207.5 kHz simplex but the requested alternate frequency is improper.
The DSC controller decoded the requested voice frequency as 4207.5 kHz simplex and your DSC controller has automatically set-up your transceiver and therefore the requested alternate frequency is correct.
The DSC call came in on 4 MHz DSC. You should set-up your transmitter and respond on the appropriate voice follow-on frequency of 4177.5 kHz.
The DSC call came in on 4 MHz DSC. You should set-up your transmitter and respond on the appropriate voice follow-on frequency of 4207.5 kHz.
What are potential dangers of automatic transceiver switching in response to a DSC call?
Incorrectly formatted DSC calls from other vessels result in a warning in the DSC alarm screen but the vessel still might be switched to an illegal or improper outcome.
Correct Answer
The transceiver may be switched out of the marinebands or the frequency may not match the requested priority or emission.
The automatic transceiver switching software always detects improper priorities, emissions & frequencies to ensure there is no danger.
The automatic transceiver switching feature always interrupting safe navigation of your own vessel and placing the unit on the GMDSS Distress, Urgency or Safety follow-on frequencies.
Which of these would not be a bad outcome of an Urgency DSC call to all vessels specifying an alternate TELEX frequency & emission that cause your transceiver to automatically switch?
The DSC controller decoded the contents of the DSC call and the requested frequency is not on the DUS table/placard but is in the marine band frequencies in the J2B emission.
The DSC controller decoded the contents of the DSC call and the requested frequency is on the DUS table/placard in the J3E emission.
Correct Answer
The DSC controller decoded the contents of the DSC call and the requested frequency is on the DUS table/placard in the J2B emission.
The DSC controller decoded the contents of the DSC call and the requested frequency is not on the DUS table/placard, is not in the marine band or the other vessel requested a J3E emission.